<title>New tool for determining diode laser beam intensity profiles in military weapon simulators</title>

Abstract

ABSTRACT The paper presents recently developed CAD capabilities which allow the precision design of the zones in MILES lasersused for force-on-force training. Effects of dynamic atmospherics are quantitatively addressed. A graphical user interface(GUT) is presented. The system designer is allowed to do what if' laser and detector designs with the goal of accuratelyemulating combat outcomes. Algorithms are described for laser radiation field calculations, target detector geometry, and themodeling of dynamic atmospheric effects. Kill zone plots are presented. Use of the software to explore design options forarea effect weapons is described, as is use of the software to explore the effects of recoil.Keywords: laser, combat training, MILES, tactical engagement system, CAD, atmospheric propagation 1 MILES HISTORY AND DESIGN TASK In the early 1970's individuals at the Army Communication Command at Ft. Belvoir and the Naval Training EquipmentCenter in Orlando, FL noticed that diode lasers were rugged enough for combat conditions, and could be focused wellenough to simulate infantry and armor weapons at range. Development was started and MILES (for Multiple IntegratedLaser Engagement System) was deployed in the early 1980's. There are currently hundreds of thousands of MILES systemsin use, and the total market over the last 20 years has reached over a billion dollars. Cubic Defense Systems Inc (CDS) iscurrently developing, under Army Contract, the next generation MILES system, MILES 2000.MILES allows force-on-force training with a highly realistic tactical result. Each player has a laser weapon and is outfittedwith laser detectors. If he is by another player's laser, then his own laser weapon is disabled. Signature devices andblanks give away the position of the firerjust as with real weapons. Umpires are still required, but only to insure that playersfollow the rules. Units train at their home station and at training centers, such as Fort Irwin and 29 Palms, where MILES isan integral part of the training battlefield. Most of all, each player is responsible for staying alive and reaching his objective.Winning, losing, and dying are based upon the objective result of maneuver and engagement, not on thejudgement of anumpire.This paper addresses the essential design problem in MILES. The lasers must be designed so that they give the same tacticaleffect as actual weapons. An M16 laser simulator should require the same pointing accuracy and give kills within the samerange envelope as the M16 rifle. The same may be said for tank guns, machine guns, and guided missiles. The fidelity withwhich the lasers replicate actual weapons is determined entirely by a property called the kill zone—that volume in front ofan aimed laser within which a target is killed for a single round fired. If the zone is too narrow, the soldier must pointmore accurately or get closer than he really has to in combat, thus giving negative tactical training. Similarly, if it is too wideor too long, he will erroneously learn to engage from too long a range.The design is iterative. A laser design is postulated, bui1t tested, redesigned, built, and tested again. The time consumingsteps are the build and test cycles, checking the zone by taking measurements. There are short-cuts of course, buthistorically, MILES developers have spent major schedule and financial resources testing designs in the field.During MILES engineering development at Xerox Corporation in the late 1970's, an analytical approach for predicting killzones was developed by Jacobs', Gammarino, and Arnold2. The approach has been updated and is used to createMILESCAD, a computer tool which runs on a personal computer. This paper describes MILES theory, the programinterface, and the algorithms. In particular, the critical effects of atmospheric scintillation on the zone will be addressed.